Fremont Grade Separation Project

This grade separation project at that time was the largest project yet undertaken by the City of Fremont. Work included an overpass on Washington Boulevard, an underpass on Paseo Padre
Parkway between Shadow Brook Common Road and Hancock Drive to separate car and pedestrian traffic from the rail road crossing.

Also, 1.5 miles of the rail was relocated 500 ft. to the east in the area between Paseo Padre Parkway and Washington Boulevard. An overpass for the planned BART extension from the downtown
Fremont to Warm Springs Station will be built over Paseo Padre Parkway.

The retaining wall portion of the work was design-build. Raito performed this portion of the work including beams and tie-backs. Soil types in the improved zones included loose sand
and high plasticity clan.

DSM walls were installed for temporary excavation support until a concrete structure for the road-way under-crossing was built. DSM also provides permanent seepage control of subsurface
water to help reduce lateral inflow.

In addition, DSM walls were used to maintain stability for abutments of the bridge supporting the Union Pacific railroad. The bridge abutments were 22 ft. behind the retaining walls. These
walls were designed with lateral earth pressure and train surcharge from Cooper E80 loading.

A test section was performed prior to full production to verify that installation procedures and mix designs would provide sufficient strength, uniformity and permeability to meet the design
intent.

DSM production was performed in two stages, East and West. All retaining/cutoff walls were installed to EL. 10 ft. Vertical beams were inserted at 4 ft. on center in wet soil cement with
bottom EL. 13 ft. to 36 ft. depending on retaining wall height. Tie-backs were installed for the area of the deepest excavation, adjacent to traffic 22.5 ft. deep from the ground surface.